1. Field of the Invention
The present invention relates to adapting turbine meters to proving, or calibrating, field meters which are on more or less continuous duty. More specifically, the turbine meter is structured to generate enough voltage pulses per volume of fluid passing through the meter to be dependably used to periodically calibrate field meters.
2. Description of the Prior Art
The low-maintenance, low-pressure drop, turbine meter has steadily gained the confidence of industry. The accuracy of turbine meter designs has been improved enough to justify the use of these meters in calibrating field meters which measure fluid flow.
However, there has been a severe limitation on the use of the turbine meter for proving field meters which measure the fluids produced from oil wells. The turbine meter, with its limited number of blades and single electromagnetic pick-up, generates far too few pulses per barrel to provide the resolution required for providing field meters. A minimum of 10,000 pulses per barrel is usually required.
The number of blades which can be added to the turbine meter rotor is limited by the desirable pressure drop through the blades. For example, the three inch, one pick-up, turbine meter generates in the order of 2,100 pulses per barrel of fluid through the meter. Of course, this number of pulses is far below the minimum of 10,000 pulses per barrel required to give satisfactory resolution for providing or calibrating, field meters. The resolution of this meter should be increased by a factor of 6, and the present invention provides this increase.